Sliding screen door

ABSTRACT

A sliding door construction having top and bottom roller units comprising a pivoted, roller carrying bar for coaction with fixed door supporting and guiding rails. A block is slidably mounted within the framework of the door below for limiting inward pivotal movement of the roller carrying bar and is adjustable by movement along a frame member of the door by a single screw for defining the inward pivotal limit of the bar. A spring outwardly biases the bar associated with each of the top roller units to urge same into firm contact with the upper rail. Sealing means on the door coact with corresponding means on adjacent doors or fixed windows and include an astrogal providing guiding, sealing and locking functions between said door and an adjacent door.

[ Nov. 27, 1973 SLIDING SCREEN DOOR [75] inventor: Kenneth C. Thom, Birmingham,

Mich.

[73] Assignee: Kaufman Window & Door Corporation, Detroit, Mich.

221 Filed: May 28,1971

21 Appl. No: 147,962

1/1926 Anderson 49/370 X 11/1966 Rifl in 49/420 Primary ExaminerKenneth Downey Attorney-Woodhams, Blanchard and Flynn [5 7] ABSTRACT A sliding door construction having top and bottom roller units comprising a pivoted, roller carrying bar for coaction with fixed door supporting and guiding [52] US. Cl 49/420, 16/99, 49/370, rails A block is Slidably mounted within the frame 49/449 work of the door below for limiting inward pivotal [5i] llit. Cl E0511 13/02 movement of the roller y g bar and is adjustable [58] Field 0! Search 49/420, 425, 417, by movement along a frame member of the door by a 49/370 366-369 449; 16/ 105 single screw for defining the inward pivotal limit of the bar. A spring outwardly biases the bar associated with [56] References C'ted each of the top roller units to urge same into firm con- UNITE STA S PATENTS tact with the upper rail. Sealing means on the door 3,443,340 5/1969 l-lelmick et a1. 49/420 co ct with c rresponding means on adjacent doors or 345,314 7/1886 McMillan 16/105 fixed windows and include an astrogal providing guid- 2.9l3,046 11/1959 Sharp 6! 49/425 X ing, sealing and locking functions between said door C011e1' X and an adjacent door 3,284,953 11/1966 Rifkin 49/420 3,040,391 6/1962 Saunders 49/425 19 Claims, 25 Drawing Figures ,0 I U m K Z/ J A l? a 2 am 20 /7 /2 Patented Nov. 27, 1973 5 Sheets-Sheet l INVENTOR x/[fl/VZTH C 7 /0/14 MAW Z Patented Nov. 27, 1973 5 Sheets-Sheet 2 INVENTOR rfZ/VA/[TH C 740M Patented Nov. 27, 1973 5 Sheets-Sheet 4 R O T N E V m SLIDING SCREEN noon FIELD OF THE INVENTION This invention relates to a sliding door construction and more particularly to a screen door construction adaptable to use in multiple door and window units and to guiding, sealing and locking means therefor.

BACKGROUND OF THE INVENTION In recent years, sliding doors and, more particularly, substantially floor-to-ceiling window and sliding door assemblies including sliding glass and screen doors, have become very popular and have come into substantial use particularly in houses, apartments and other dwellings. Such units provide substantial advantages in providing for increased admittance of sunlight, an unobstructed view and a convenient means for entrance to and egress from the building.

However, problems have arisen in connection with use of prior units of this type, particularly with respect to sliding screen doors used in such units. Such screen doors are conventionally supported and guided by means of rollers carried thereby which engage rails fixed to the building structure above and below the door for rolling therealong. Such rails are fixed to the building structure but may often be not precisely parallel and evenly spaced and moreover may be subject to gradual relative movement due to settling of the building or portions of the adjacent structure thereof. Moreover, the precise separation between such rails may differ from installation to installation. Thus, prior doors which have not provided for adjustment or resilient mounting of the rollers have been generally unsatisfactory in meeting the above mentioned variations in rail spacing and alignment. Moreover, even where such adjustment is provided, the means forcarrying out such adjustment are often inconvenient to use, for example, by reason of their particular location on the door or a requirement for special adjusting tools.

Further, inasmuch as such sliding screen doors are typically substantially taller than they are wide, there is a natural tendency in use for same to tilt with respect to the rails or, in other words, pivot in their central plane from an upright position, which tends to make such doors jam and thus be rendered unusable or interfere with their opening and closing movements.

Further, prior sliding doors have often been subject to unlocking or removal from the building opening by unauthorized persons seeking entrance to the building. Such removal is normally carried out by moving the door upwardly until the bottom rollers thereof clear the lower rail upon which they are normally supported, moving the bottom of the door outwardly and then moving the door as a whole downwardly to disengage the upper rollers thereof from the upper rail, whereby the door is completely removed from the building, allowing entrance thereinto. This unauthorized removal can be accomplished in known prior art sliding door constructions, particularly screen door constructions, by reason of the resilient mounting of the rollers thereof which allows substantial upward travel of the door with respect to the upper guiding rail.

It is often desired to provide a window, door unit in which more than one sliding screen (or glazed) door is provided, more particularly by providing a construc- In such an arrangement problems arise in guiding the opposed, upstanding edges of the two slidable doors into an alignment with each other as they are closed, providing an insect or weather seal therebetween and providing for locking thereof with respect to each other. Moreover, it may be desired to utilize in such constructions doors which are also usable in sliding door units where only a single door is provided. The prior art does not fully resolve these problems in a simple and economical manner.

Accordingly, the objects of this invention includes provision of:

l. A sliding door construction having features particularly adapted to sliding screen doors as well as to glazed sliding doors.

2. A sliding door construction, as aforesaid, adapted to use in substantially floor-to-ceiling door units having either a single sliding glazed door and a single sliding screen door or multiple sliding screen and glazed doors wherein a pair of doors can slide together in an edge-toedge abuting relationship to close the opening into the buidling.

3. A door construction, as aforesaid, wherein the ten dency of relatively tall and narrow sliding doors to cock or tilt with respect to the rails upon which they are slidably supported is substantially eliminated and in which the vertical positioning of the door with respect to the top and bottom rails upon which same is mounted may be readily adjusted.

4. A door construction, as aforesaid, wherein means are provided to readily adjust the rollers by which the sliding door is supported and guided to compensate for misalignment or a non-horizontal condition of the rails contacted by such rollers so as to allow squaring of the door to the door jamb which it engages to close the opening into the building.

5. A door construction, as aforesaid, which prevents unauthorized lifting of the door with respect to the rails for unlatching same and for disengaging the rollers thereof from the supporting and guiding rails of the building and thereby eliminates the thread of unauthorized entry into the building by removal of the door or disengagement of the latch.

6. A door construction, as aforesaid, in which means are provided for limiting the travel inwardly and outwardly, with respect to the door, of the supporting rollers thereof which means are durable, capable of a long service life under adverse conditions, including conditions of relatively high heat as may be encountered during hot summer weather when the door construction is directly exposed to the sun.

7. A door construction, as aforesaid, in which the travel or orbit of the roller inwardly and outwardly of the portion of the door'upon which same is mounted, and more particularly the extend to which same can travel inwardly with respect to the door, may be preselected, prior to use and during assembly or thereafter, in an extremely simple way and with inconsequential or no incrased cost, without use of means provided for adjustment of the inward limiting position of the roller with respect to the door.

8. A door construction, as aforesaid, in which the location of the rollers with respect to the central plane of the door can be readily changed during manufacture to allow use of the door with any of a wide variety of track constructions.

9. A door construction, as aforesaid, in which a large proportion of the parts comprising the door and roller mounting may be made economically and with little labor through wide use of extrusions.

10. A door construction, as aforesaid, including a removable astrogal unit particularly adapted to use in units wherein a pair of substantially coplanar doors are movable into and out of edge abutting relationship to close and open the portal and which simply and economically provides for guiding of the doors into a precisely aligned abutting relationship, provides for wind and weather sealing therebetween and provides means for locking same together.

Other objects and purposes of this invention will be apparent to persons acquainted with apparatus of this general type upon reading the'following specification and inspecting the accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is an elevational view of a window and door unit embodying the invention as seen from the interior of a building structure into which same is incorporated.

FIG. 2 is a partially broken, enlarged elevational view of the leftward screen door of FIG. 1.

FIG. 3 is a reduced, partially broken, rightward elevational view of the door of FIG. 2, additionally showing rails for guiding and supporting such door.

FIG. 4 is a partially broken, leftward end elevational view of the door of FIG. 2.

FIG. 5 is a partially broken, sectional view substantially taken along the line V-V of FIG. 2.

FIG. 6 is a partially broken, sectional view substantially taken along the line VIVI of FIG. 2 and additionally showing coaction of the door with an adjacent window unit. FIG. 7 is a partially broken, sectional view taken along the line VII-VII of FIG. 2.

FIG. 8 is a partially broken, sectional view taken along the line VIII-VIII of FIG. 2.

FIG. 9 is an enlarged, partially broken sectional view substantially as taken along the line IX-IX of FIG. 3.

FIG. 10 is a partially broken, sectional view taken along the line X-X of FIG. 9.

FIG. 11 is a partially broken, sectional view taken along the line XI-XI of FIG. 9.

FIG. 12 is a sectional view taken along the line XII- --XII of FIG. 9.

FIG. 13 is an enlarged sectional view taken along the line XIII-XIII of FIG. 4.

FIG. 14 is a fragmentary, pictorial view disclosing a modified roller mounting.

FIG. 15 is a pictorial view disclosing a modified adjustment block construction.

FIG. 16 is an exploded, pictorial and fragmentary view disclosing a modified roller mounting bar.

FIG. 17 is a partially broken, elevation view of an astrogal adapted for use with a door construction of FIG.

FIG. 18 is an enlarged fragmentary sectional view substantially taken along the line XVIII--XVIII and disclosing the use of an astrogal with a pair of relatively movable doors.

FIG. 19 is an enlarged sectional view substantially taken along the line XIXXIX of FIG. 17 and disclosing the use of the astrogal in connection with a pair of relatively slidable and abutable doors and showing a lock feature thereof.

FIG. 20 is a reduced sectional view taken on the line XXXX of FIG. 18.

FIG. 21 is a cross-sectional view of a lock arrangement for the door construction of FIG. 2.

FIG. 22 is a sectional view substantially taken along the line XXI-XXI of FIG. 20.

FIG. 23 is an exploded pictorial view of portions of the apparatus of FIG. 20.

FIG. 24 is an exploded, pictorial view disclosing a further modified roller mounting bar.

FIG. 25 is a pictorial view disclosing a further modified adjustment block construction.

Certain terminology will be used in the following description for convenience in reference only and will not be limiting. The words up, down, right" 'and left will designate directions in the drawing to which reference is made. The words in and out" will refer to directions toward and away from, respectively, the geometric center of the device and designated parts thereof. Such terminology will include derivatives of the above terms and words of similar import.

SUMMARY OF THE INVENTION The objects and purposes of the invention are met by providing a sliding door construction having top and bottom roller units comprising a pivoted roller carrying bar arranged for coaction with fixed door supporting and guiding rails. A block is slidably mounted within the framework of the door for limiting inward pivotal movement of the roller carrying bar and is adjustable by movement along aframl: member of the door by a single screw for defining the inward limit position of the bar. A spring outwardly biases the bar associated with each of the top roller assemblies to urge same into firm contact with the upper rail. Sealing means on the door coact with corresponding means on adjacent doors or fixed windows and include an astrogal providing guiding, sealing and locking functions between said door and an adjacent door.

DETAILED DESCRIPTION FIG. 1 discloses a door assembly 10 embodying the invention, as seen from the interior of a building, the door assembly being located in an opening 14 in a wall 1 1 of the building. The bottom of the door assembly is substantially at the level of the floor 12 and the top of the assembly 10 is disclosed as being located adjacent the ceiling of a room in such building. The door assembly 10 includes a pair of fixed glas panels 16 and 17 which may be of conventional nature and a pair of horizontally slidable doors 19 and 20.

The doors l9 and 20 are in the preferred embodiment shown slidable screen doors but it is contemplated that slidable glass doors may be provided in addition thereto in any conventional manner for providing additional coverage of the space between the fixed windows 16 and 17, such additional glass doors not being shown. In addition, it is contemplated that the doors 19 and 20 themselves may be glazed, rather than screened, doors. Conventional upper and lower tracks 22 and 23 are provided in the door assembly 10 for supporting and guiding the screen doors l9 and 20 for sliding movement parallel to the plane of the wall 11 and fixed windows 16 and 17. The upper track 22 is preferably fixed within the opening 14 in the wall 11 and to the upper edge 25 of such opening in a conventional manner and the lower track 23 is preferably fixed in a conventional manner to the lower edge 26 of the-building opening 14 preferably substantially at the level of the floor 12 and in vertically spaced opposition to the upper track 22, the tracks being at least substantially horizontal and parallel. However, it is often the case with known sliding door assemblies that the upper and lower rails thereof when actually installed in an opening in a building structure may deviate from true parallelism with each other and/or from a strictly horizontal condition. Thus, as mentioned above, the door construction embodying the present invention hereinafter discussed is, as one of its aspects, intended to operate satisfactorily despite such deviations in the arrangment of the tracks with which it is associated and indeed to overcome such shortcomings of the tracks and trackmounting. The door 19 may be used in other door assemblies than the door assembly shown, for example, door assemblies wherein a second door 20 is not provided and wherein the rightward edge of the door 26 engages a fixed portion of the door assembly when closed. The doors 19 and 20 are preferably of similar construction and more particularly preferably are substantially mirror images of each other as viewed from the top thereof. Thus, a description of the door 19 will also suffice for the door 20 except as hereinafter noted with respect to particular features such as the provision for latching and the arrangement of the astrogal, hereinafter described, between the doors l9 and 20.

The door 19 (FIG. 2) comprises a parallel, spaced pair of normally vertically oriented side members 29 and 30 joined at their upper and lower ends, respectively, by a top member 31 and a bottom member 32, which are normally horizontally disposed and which are parallel to each other, the members 29 through 32 defining a rectangular door framework. The members 29 through 32 are preferably extrusions of anodized aluminum. The side member 30 carries a latch assembly 34 hereinafter discussed.

As seen in FIG. 5, the side members 29 and 30 are of hollow, substantially rectangular cross-section, each having spaced interior and exterior walls 36 and 37, which are parallel to the central plane of the door 19, and spaced inner and outer walls 38 and 39, which are normal to the central plane of the door 19. The side member 39 is provided with a generally L-shaped flange 41 which extends interiorly from the wall to the juncture of the walls 37 and 39 and then inwardly in parallelism with the wall 37. The L-shaped flange 41 coacts, as seen in FIG. 6, with a similar flange 42 on the framework of the fixed window 16, the flanges 41 and 42 being engageable in close spaced interfigured relationship as seen in FIG. 6,when the door 19 is in its closed position of FIGS. 1 and 6. Weather seals at 47 and 48 are disposed in the pockets defined by the flanges 41 and 42 to provide weather and/or insect sealing between the window 16 and door 19 when the latter is in its closed position shown and further providing a stop for limiting rightward motion as seen in FIGS. 1 and 6 of the door 19 with respect to the window 16.

Whereas the walls 36 through 38 of the side members 29 and 30 and the outer wall 39 of the side member 29 are preferably planar, the outer wall 39 of the side member 30 has a depressed central portion 50 (FIG. 5) connected to the outer portions of the outer wall 39of side member 30 by outwardly diverging portions 52.

The top and bottom membersg31 and 32 (FIG. 8) are substantially similar in cross-section and preferably have cross-sections which are mirror images of each other. The members 31 and 32 are substantially channel-shaped in section, the upper member 31 opening upwardly and the lower member 32 opening downwardly. Thus, the top and bottom members eachcomprise interior and exterior sidewalls 55 and 56, respectively. The sidewalls 55 and 56 are joined at their inner edges by an inner wall 57. A pair of spaced, parallel sidewall extensions 58 and 59 extend outwardly beyond the free edges of the sidewalls 55 and 56, respectively, are preferably parallel to the central plane of the door 19 and are preferably offset outwardly from said plane, by approximately the thickness of the sidewalls 55 and 56. The sidewalls 55 and 56 and sidewall extensions 58 and 59 are preferably planar and parallel to the central plane of the door 19. The inner wall 57 is preferably planar and perpendicular to the central plane of the door 19 and hence to the sidewalls 55 and 56.

A hollow, split rib 61 is preferably centered on and extends outwardly from the inner wall 57 as well as extending lengthwise therealong. The rib is defined by a pair of spaced, outwardly convex flange elements defining, with the inner wall 57, a semi-circular shell extending through more than 180, for example through approximately 270, for substantially enclosing a circular, longitudinally extending opening 63.

The inner walls 38 and 57 (FIGS. 5 and 8) of the side, top and bottom members 29 through 32 of the door 19 each have preferably centrally located thereon an L- shaped screen edge retaining flange 65 for defining a groove for receiving the edge of a sheet of screening 67 held in place therein by a conventional plastic strand 68 wedged with the screen edge thereinto.

The end portions of the inner walls 38 of side members 29 and 30 are recessed as indicated at 70 (FIGS. 8 and 9), the recess 70 extending fully between the interior and exterior sidewalls 36 and 37 of the side members 29 and 30. The depth and width of the recess 70 corresponds to the width dimensions of the sidewalls 55, 56 and inner wall 57, respectively, of the top and bottom members 31 and 32.

Thus, the ends of the top and bottom members 31 and 32 are inserted through the recesses 70 into the interior of the side members 29 and 30 and extend across the interior of such side members into abutting relationship with the outer walls 39 of the side members 29 and 30. Because of the depressed central portion 50 of the outer wall 39 of side member 30, the free end of the inner wall 57 of the top and bottom members 31 and 32 disposed within side member 30 is relieved as indicated at 72 (FIG. 5) to a depth sufficient to receive therein the depressed portion 50 while allowing the adjacent free ends of the sidewalls 55 and 56 of such top and bottom members 31 and 32 to extend along the outwardly divergent portions 52 into contact with the outer parts of the outer wall 39 of side member 30. The sidewall extensions 58 and 59 extending outwardly beyond the side members 29 and 30. Because of the outward offset of the sidewall extensions 58 and 59, the outer surfaces there of are substantially coplanar with the outer surfaces of the interior and exterior walls 36 and 37 of the side members 29 and 30. Thus, the ends of the hollow spilt ribs 61 and bottom wall 57 extend into close adjacency with and preferably contact the adjacent portion of the outer wall of the corresponding one of the side members 29 and 30.

As illustrated in FIGS. 9 and 13, the end walls 39 of side members 29 and 30 are provided with holes 74 coaxially aligned with the opposed split ribs 61 for receiving screws 75, preferably of the self-tapping type, which threadedly engage the end portions of the opposed hollow split rib 61 for reception therewithin and between the flange element 62 thereof.

Thus, the framework of the door 19 is formed by nesting the top and bottom members 31 and 32 in the recesses 70 of the side members 29 and 30 and held together at each comer by a single screw 75, for providing a rigid and yet very rapidly assembled, or if need by disassembled, door framework.

The door 19 is mounted for sliding movement along the upper and lower tracks 22 and 23 by upper and lower roller assemblies 79 and 77, respectively (FIGS. 3, 6 and 7). One lower roller assembly 77 is preferably located in the lower member 32 adjacent each end thereof. Similarly, one upper roller assembly 79 is preferably disposed substantially within the upper member 31 adjacent each end thereof.

The upper and lower tracks 22 and 23 may take any of a number of conventional forms. In the particular embodiment shown, the upper track 22 includes a depending rail 81 (FIG. 3) having a lower edge surface disposed between the interior and exterior walls of the top frame member 31 and engageable with the upper roller assemblies 79. The upper track 22 includes a leg 82 which extends exteriorly of the rail 81 and downwardly and in spaced opposition with the exterior wall 59 of top frame member 31, the leg 82 carrying conventional weather stripping 83 which bears slidably against the outersurface of the wall 59. Similarly, the bottom track 23 includes an upstanding rail 85 disposed between the interior and exterior walls of the bottom member 32 for engagement with the roller support assemblies 77. The lower track 23 further includes a portion 86 spaced in opposition to the exterior wall 59 of bottom member 32 and carrying suitable weatherstripping 87 slidably engageable with the wall 59.

The upper roller assemblies 79, as seen in FIG. 6, are preferably mirror images of each other. The lower roller assemblies 77 are also, as seen in FIG. 7, preferably mirror images of each other. Thus, a description of one of the upper roller assemblies 79 will suffice for both and a description of one of the lower roller assemblies 77 will suffice for both. Further, the lower roller assemblies 77 are also generally similar in construction to the upper roller-assemblies'79 except as hereinafter discussed in detail. Thus, a detailed description of the rightward one of the upper roller assemblies 79 will also suffice for the lower roller assemblies 77, parts of the lower roller assemblies 77 corresponding to parts of the upper roller assemblies 79 carrying the same reference numerals thereas with the suffix A added.

The roller assembly 79 includes a pivot bar or lever 91 (FIGS. 9-11) which in the particular embodiment shown is of substantially rectalinear form. The bar 91 is pivotally supported at a point intermediate its longitudinal mid-point and rightward end, by a pivot pin 92 extending through a transverse opening 93 in the bar 91. The pin 92 extends beyond the sides of the bar 91 and is received, preferably fixedly, in openings 94 (FIG. 6) in the sidewalls 55 and 56 of the top frame member 31 of the door 19. The ends 95 of the pin 92 are preferably flush with the outer faces of the sidewalls 55 and 56 and when the door 19 is in its assembled condition are covered by the opposed end portions of the sidewalls 36 and 37 of the corresponding side member 36.

A stub shaft 97 (FIGS. 9 and 12) is snugly received in a transverse opening 98 in the bar 91 adjacent its leftward end for supporting a roller or wheel 99. The bar 91 has a notch 101 adjacent its leftward end (FIGS.

6, 10 and 12) for receiving the roller 99 loosely therewithin. In the particular embodiment shown, the rail 81 with which the roller 99 coacts is spaced, as seen in FIG. 3, somewhat exteriorly from the central plane of the door 19 rather than being in the central plane of the door. Thus, the roller 99 and the cutout portion of the bar 91 are located exteriorly of the central plane of the door 19 and of the bar 91. However, it is contemplated that upon different location of the rail 81 with respect to the central plane of the door that both the roller and the cutout portion for receiving same may be correspondingly relocated on the bar 91.

The stub shaft 97 extends into the notch 101. In the preferred embodiment shown, a sleeve 103 (FIG. 12) is supported on the free end of the stub shaft 97 and secured thereto by flaring of the free end of the stub shaft as indicated at 104, as by upsetting the end of the stub shaft after the sleeve is installed. The sleeve 103 carries spaced annular retainers 105 and 106 fixed thereto by any convenient means such as pressed fitting. The roller 99 is rotatably supported on the sleeve 103 between the retainers 105 and 106.

The roller 99 has a narrowed radially inner portion 107 disposed between the retainers 105 and 106 and an outwardly facing, preferably hemicircular, circumferential groove 109 which is preferably complimental in shape to the rail 81 at the zone of contact therebetween. Thus, the roller 99 rolls on the rail 81. By reason of the sidewalls of the groove 109, the roller 99 resists transverse, that is, exterior or interior movement, with respect to the rail, thereby tending to prevent interior or exterior movement of the door 19 with respect to the track 22.

In the particular embodiment shown, the portion of the sidewall 56 adjacent the roller 99 is relieved to form a shallow pocket 110 (FIGS. 9 and 12) to allow free pivotal movement of the lever or bar 91 upwardly and downwardly about the pin 92 without interference of the roller 99 or retainer 105 with the exterior wall 56.

Each roller assembly 79 includes a pivot limiting mechanism generally indicated at 112 comprising a limit block or nut 114 (FIGS. 9 and 12) which in the particular embodiment shown is substantially rectalinear in shape. The nut 114 is snugly but slidably disposed between the sidewalls 55 and 56 of the frame member 31 and slidably rests atop the inner wall 57 of the member 31. The lower end of the nut 114 is provided with a recess 115 which is preferably hemicircular in shape at its closed end as indicated at 116. The recess 115 loosely accommodates the split rib 61 upstanding from the bottom wall 57.

The end of an elongated adjustment screw 118 is threadedly received in a preferably centrally located threaded opening 119 located in the nut 114 above the recess 115. A stop element 120, here a conventional cotter pin, is fixed to the screw 119 at the leftward end thereof as seen in FIG. 9 for preventing unintended removal of the nut 114 from the free end of the screw 118 and also thereby providing a limit to leftward movement of the nut 114 with respect to the screw 118 and the remainder of the roller assembly 79. The upper end 121 of the nut 114 is spaced above the screw 118 for contacting and thereby limiting downward or inward movement of the pivot bar 91 and roller 99 carried thereby. The rightward end of the screw 118 is provided with a conventional slotted head 122. The rightward end of the screw is received in and rests adjacent the bottom of a slot 124 (FIGS. 3 and 9) in the outer wall 39 of the frame side member 30, the head 122 being disposed against the outer face of the wall 39 for preventing leftward (as seen in FIG. 9) movement of the screw therebeyond.

An axially elongate, coiled spring 125 and washer 126 coaxially surround the screw 118. The spring 125 is located between the nut 114 and the washer 126. The washer 126 is adapted to bear against the inner face of the outer wall 39, the spring 125 continuously urging the nut 114 against its threaded engagement with the screw 118 in a direction away from the wall 39 and tending to prevent unintended rotation of the screw 118 and, hence, shifting of the nut 1 14 axially with respect thereto.

The screw 1 18 is rotatable for positively adjusting the location of the nut l 14 longitudinally of the member 31 and, hence, substantially longitudinally of the pivot bar 91. Thus, by adjustment of the screw the nut can be moved rightwardly therealong towardthe pivot pin 92. The upper end 121 of the nut 114 is preferably located a sufficient height above the wall 57 of member 31 that the pivot bar 91 during inward movement thereof contacts same before having assumed a horizontal position. Thus, rightward adjustment of the position of the nut 114 increasingly prevents counterclockwise pivotal movement of the pivot bar 91 or in other words increases the height of the lowermost position that can be assumed by the roller 99. Thus, the innermost position of the roller 99 and pivot bar 91 is dictated by the position of adjustment of the nut 114. The innermost position of the roller 99, with the nut in its position shown in FIG. 9, is indicated in broken lines at 99'.

In the particular embodiment shown, the pivot pin 92 is sufficiently close to the screw 118 that the rightward end of the bar 91 would contact the spring 118 upon being rotated in a clockwise direction only a small distance from its innermost limiting position 99'. Thus, the lower surface of the rightward end of the pivot bar 91 is provided with a centrally located groove 127 (FIGS. 9 and preferably of semicircular crosssection, of radius exceeding that of the spring 1 18 and of rightwardly (as seen in FIG. 9) increasing depth. Thus,clockwise pivotal movement of the pivot bar 91 in FIG. 9 is ultimately limited by' contact of the spring 118 with the bottom of the groove 127 to define the outward limiting position of the roller 99, indicated in broken lines at 99", which position in the present embodiment is one in which at least the upper edge of the roller extends upwardly beyond the upper edge of the member 31. r

As above indicated, the construction of the lower roller assemblies 77 are preferably identical to that of the upper roller assemblies 79 to the extent that the latter have been described above. However, it will be noted that in view of the different functions of the upper and lower roller assemblies, it may be desired to provide nuts 114A in the lower roller assemblies 77 (FIG. 13)

which differ in height from the nuts 114 used in the upper roller assemblies 79, as discussed hereinafter.

The upper roller assemblies 79 differ further from the lower roller assemblies 77 in that a bias spring preferably in the form of a sinously curved leaf spring 129 is provided in each of the upper roller assemblies 79 for urging the pivot bar upwardly and outwardly with respect to the door 19 and thereby for resiliently urging the roller 99 into contact with the coacting rail 81 of the upper track 22. Thus, the spring 124 causes the roller to remain in door guiding contact with the rail 81 despite misalignment of the tracks 22 and 23, for example, nonparallelism of the tracks, nonlinearity of a track, etc.

In the preferred embodiment shown, the leaf spring 129 comprises a single, resilient and substantially rectangular sheet of spring material which for the major portion of its length and in the central portion thereof is convexly curved outwardly and leftwardly as seen in FIG. 9. The spring 129 has a short, reversed curve portion 132 at the leftward end thereof forming a foot for slidably bearing against the upper end of the split rib 61. The rightward end 133 of the spring 129 is substantially channel-shaped, extending substantially upwardly to define a bight portion 134 and then substantially leftwardly to define a tip 136. The bight portion 134 is snugly received and retained in a narrow slot 135 in the pivot bar 91 adjacent the leftward upper end of said bar. The slot 135 opens in the exterior face of the pivot bar 91 in the cutaway portion 101 thereof. In the particular embodiment shown, the spring 129 is retained endwise of the slot 135 by the roller retainer 106. The adjacent tip 136 of the spring overlies the leftward end of the pivot bar 91. Thus, the rightward end 133 of the spring 129 grips the bar 191 by reason of the portions of said spring immediately adjacent the bight portion 134.

FIG. 14 discloses a modified pivot barconstruction 918 wherein the roller 99B is disposed at or near the center of the bar rather than adjacent one edge thereof. More particularly, the bar 91B is provided with a substantially centrally located notch 140 of preferably rectilinear shape which receives the roller 993. A stub shaft 97B is fixed to and extends between the legs 141 and 142 bounding the notch 140 for carrying the roller 998. The construction of FIG. 14 may be used, for example, wherein the rails 81 and 85 (FIG. 3) are located in or adjacent the central plane of the door ratherthan to one side thereof.

FIG. 15 discloses a modified limit block or nut construction 114B. the nut 114B is preferably a metal, such as aluminum, extrusion, individual ones of the nut 114B being manufactured by severing short lengths from a continuous or elongate extrusion of corresponding cross-section. The nut 114B differs from the nut 1 14 above discussed with respect to FIGS. 9-13 in having relieved portions 144 in each of the side faces 146 and 147, intermediate the top and bottom edges thereof, to reduce surface contact and, hence, friction between the nut 1143 and the sidewalls 55 and 56 (FIG. 12) of the top or bottom member 31 or 32 in which same is disposed. The relieved portions 144 also save material.

The nut 1148 is also provided with a slot 146 communicating between the recess 1158 and the threaded opening 119B, the slot 146 being provided to facilitate the extrusion process. The slot 146 is relatively narrow and in no way interferes with the coaction of the threaded opening 1198 with the adjustment screw 118 or with other functions of the nut 114B.

FIG. 16 discloses a modified form of the pivot bar as indicated at 91C. The pivot bar 91C is particularly adapted to construction in the form of an elongate extrusion, individual ones of the pivot bars 91C being obtained from such an elongate extrusion by severing short lengths therefrom. Moreover, the configuration of the pivot bar 91C provides adequate strength and all the functional capabilities of the pivot bar 91 of FIGS. 9-13 while effecting a considerable saving in the amount of material required. Bar 91C comprises a substantially rectilinear body portion 148 provided at the leftward end thereof, as seen in FIG. 16, with a substantially rectilinear extension 149 which is of reduced thickness and is slightly angled with respect to the length dimension of the body portion 148. The underface 151 of the extension 149 is adapted to serve the purpose of the central groove 127 (FIG. 9) of the bar 91, namely in normally allowing the pivot bar 91C to clear the adjustment screw 118 and its surrounding spring 125 but to bear against the periphery of the spring 125 to limit outward pivotal movement of the pivot bar.

At or adjacent the joint of the extension 149 to the body portion 148 there is provided, at the top the body member 148, a transversely extending, hollow, slotted boss 152 defining therein a passage 153 corresponding to the pivot pin opening 93 of FIG. 9 and for reception thereinto and therethrough of a pivot pin 92C. A further and similar hollow, slotted boss 155 is provided on the upper face of the body portion 148 in spaced relation to the boss 152 and adjacent the rightward end of the body member 148. The passage 156 defined by the boss 155 serves the function of the opening 98 in the pivot bar 91 of FIG. 9, the passage 156 thus receiving therewithin a stub shaft 97C for supporting roller 99C on and beside the pivot bar 91C. The width of the body portion 148 and extension 149 preferably corresponds to the width of the-pivot bar 91 of FIG. at the notch At the rightward tip of the pivot bar 91C there is pro vided a generally L-shaped slot 158 extending transversely of the body portion 148 and having an upwardly extending portion and a rightwardly opening portion. A spring 129C is provided with a narrow, transversely extending flange 159 receivable in the slot 158. The flange 159 is held in fixed relation to the body member 148 by the edge portion 161 of the body member 148, which defines the L-shaped slot 158. After insertion of the leftward end of the spring 129C into the slot 158, the edge portion 161 is deformed to narrow the bottom of the slot 158 and, hence, tightly grip the flange 159 of the spring 129C.

Where the door 19 is to be aligned with a further door 20, as in the embodiment illustrated in FIG. 1, the preferred embodiment of the invention provides an elongate alignment, sealing and locking strip or astrogal 165 (FIGS. 17-20). The astrogal 165 is preferably formed as an extrusion, preferably of metal such as aluminum. As seen in FIG. .18, the astrogal 165 has an interior portion 166 which is generally of C-shaped crosssection, comprising a bight wall 167 connecting a pair of divergent walls 168 and 169. The divergent walls 168 and 169 terminate in a pair of convergent walls 170 and 171, the free edges of which are spaced from each other by a distance corresponding substantially to the width of the bight wall 167. The width of the bight wall 167 and the acute angle between the divergent walls 168 and 169 are such as to allow same to be snugly but readily received into the depressed central portion 50 of the side member 30 of door 19, the divergent walls 168 and 169 paralleling the outwardly divergent portions 52 associated with the depressed portion 50. The convergent walls and 171 are arranged for similar snug but ready reception into the opposed depressed portion 50D of the corresponding opposed side member 30D of door 20, the convergent wall 170 and 171 preferably paralleling the divergent walls 169 and 168, respectively, and being of width similar thereto.

Bight wall 167 is provided with a plurality of spaced openings distributed longitudinally thereof for reception' of screws 175 which threadedly engage suitable threaded openings 176 in the depressed portion 50D of the door 20 for securing theastrogal 165 to the door 20 in nesting relation within the depressed portion 50D.

The astrogal 165 further includes an exterior portion 177 of generally T-shaped cross-section having a cross arm 178 and central leg 179 connecting the midpoint of the cross arm 178 to the juncture of the exteriorily facing divergent and convergent walls 168 and 170. The leg 179 is of sufficient length to dispose the crossarm 178 so that its interior face snugly abuts the exterior face of side member 30D of the door 20 and will snugly but slidably receive the exterior face of the side member 30 of door 19 therepast. Thus, the groove-like space between the crossarm 178 and the convergent sidewall 170 normally snugly receives the exterior edge of the door 20 while the exterior edge of the door 19 is slidably but snugly receivable into the corresponding groove-like space between the crossarm 178 and the divergent wall 168. The crossarm 178 and divergent wall 168 guide the edge of the door 19 into a closed coplanar relationship with door 20. The labyrinthian character of the opposed faces of the astrogal 165 and door 19 tends to act as a weather or insect seal.

As seen in FIGS. 17 and 20, the astrogal 165 is provided with longitudinally extending, rounded end openings 181 and 182 adjacent the ends thereof which allow access to adjustment screws on the door 20 corresponding to adjustment screws 122 and 122A of the door 19 (FIG. 3). The openings 181 and 182 also allow access to screws which hold the frame of the door 20 together corresponding to the screws 75 of FIG. 3. The openings are aligned, longitudinally of the astrog'al, with the screws 176 above mentioned, and hence are substantially centered on the bight wall 167 of the astrogal.

The ends of the astrogal 165 are provided with longitudinally extending, rounded-end notches 184 and 185 which are laterally offset from the openings 181 and 182, being provided through adjacent portions of the bight wall 167, divergent wall 168 and leg 179. The notches 184 and 185 provide clearance for the rails 81 and 85 upon which the doors 19 and 20 are supported and guided.

A preferably rectangular, longitudinally extending latch opening 187 is provided in the bight wall 167 for reception thereinto of a generally L-shaped and vertically movable latch element 189 (FIGS. 2, 3, 19 and 20) which comprises the operative portion of the latch assembly 34 on door 19. The opening 187 is located longitudinally of the astrogal 165 and door in a manner that the upstanding leg 190 of latch element 29 may be located within the interior of the C-shaped astrogal portion 166 above the upper edge of latch opening 187, whereby coaction between the portion of bight wall 167 immediately above the latch opening 187 with the.

as shown, in which case the bottom edge of the astrogal opening 187 is located for coacting with the latch element leg 190 to enable latching and unlatching thereof.

Where it is desired that only one sliding screw or glazed door be utilized, such as the door 19, instead of both doors 19 and 20, the astrogal 165 and door 20 may be replaced as seen in FIGS. 21-23 by a fixed stile 193 and a hollowed latch block 194. The stile 193 may be of any convenient material such as wood and may be part of the framing for the building opening in which the door assembly is disposed. The inward face 196 of the stile 193 is stepped as indicated at 197 and 198 so that the exterior face 199 of the stile extends furthest into the building opening in which the door 19 is disposed. The latch block 194 is preferably formed as a rectilinear, hollow element having an interior face 201, end walls 202 and 203 and sidewalls 204 and 205 defining a'recess or hollow interior 206. A preferably rectangular notch is provided in the sidewall 204, preferably by removal of the central portion of the sidewall, for receiption of the latch element 189. Longitudinally elongated slots are provided through the interior face 201 along the edge thereof opposite the opening 208.

The block 194 is snugly received within the step portion 198 of the stile 193 with the recess 206 thereof facing exteriorily and the free edges of the walls 202, 203 and 206 bearing on the interiorly facing portion of the step portion 198. The block 194 is held in such position by screws 210 extending through the slots 209 and into threaded engagement with the material of the stile 193. The block 194 extends beyond the step 197 and the face 204 is arranged to be disposed in close adjacency to the depressed portion 50 in the opposed edge of the closed door 19 in the region of the latch element 189. Thus, the leg 190 may be received through the opening 208 in the block 194 and when moved into latching position, as shown in FIG. 22, the leg 190 snugly but slidably bears against the interior face of the sidewall 204, here at the upper edge of the notch 208, for holding the door 19 closed. The slots 209 allow, upon loosening of the screws 210, upward or downward adjustment of the latch block 194 for providing maximal overlap of the latch element leg 190 and the wall 204 in the latching position shown in FIG. 22 but allowing the leg 190 to be removed through the opening 208 when in the unlatched position to allow opening of the door 19.

OPERATION Although the operation of the embodiment of the invention above described will be understood from the foregoing description by skilled persons, a summary of such description is given below for purposes of convenience.

The door 19 is quickly and readily assembled from the side members 29 and 30 and top and bottom members 31 and 32 (FIGS. 2-8) by insertion of the ends of the top and bottom members 31 and 32 in the recesses in the tops of the side members 29 and 30, wherein the side member ends are snugly received throughout substantially the entire width of the side members 29 and 30. The side members are fixed to the top and bottom members by the screws 75, there being one such screw for each corner of the door, each screw passing through the wall 39 of the corresponding side member at the hole 74 (FIG. 9) and being held in selfment screw 118 and 118A, nuts 114 and 114A, springs 125, rollers 99 and 99A and pivot bars 91 and 91A therein, each pivot bar being secured within the respective one of the top and bottom members by its respective pivot pin 92 or 92A. The portion of each adjustment screw 118 adjacent the head 122'is received in the slot 124 in the adjacent side member as the top or bottom members are received in the side members, the head 122 and washer 126 being disposed on opposite sides of the slot 124.

Installation of the door 19 into guided and supported relationship with respect to the rails 81 and of tracks 22 and 23 is readily accomplished by adjustment, if required, of the adjustment screws 118 and 118A of the upper and lower roller assemblies 79 and 77, respectively, to allow each of the pivot bars 91 to assume a position at or adjacent its inwardmost limiting position 99' (FIG. 9) and further to allow each of the pivot bars 91A to assume an inward limiting position such that the roller 99A associated therewith is spaced above the lower edge of the bottom frame member 32. With the roller assemblies so arranged, the upper edge of the door 19 is raised upwardly so that the rollers 99 thereof contact the upper rail 81. The door thereafter is raised further to depress the springs 129 and move the pivot bars 91 into limiting contact with the opposed adjustment nuts 114 so that the door is raised to the fullest extent possible with respect to the rail 81. Thereafter, the lower edge of the door may be swung interiorily, the bottom edge of the door clearing the lower rail 85 and the pivot bars 99A being swung upwardly to their innermost limiting position, defined by the nuts 114A, to also clear the rail 85. Thereafter, with the rollers 99A positioned directly over the lower rail 85, the door is allowed to drop so that the rollers 99A rest is guided, supported relation upon the lower rail 85. The springs 129 urge the pivot bars 91 of the upper roller assemblies 79 upwardly to maintain guided contact between the rollers 99 and the upper rail 81 associated therewith.

Thereafter, the adjustment screws 122A of the lower roller assembly 77 are rotated by engagement of the heads 122A thereof by a screwdriver to move the adjustment nuts 114A outwardly. Since the weight of the door 19 causes the pivot bars 91A to bear against the nuts 114A, such adjustment causes the pivot bars 91A and rollers 99A to move downwardly to raise the door on the track 23. This, of course, will cause a corresponding depression of the rollers 99, which is allowed by the bias spring 129 of each of the upper roller assemblies. Such adjustment is continued until the op posed edges of the rails 81 and 85 contact by the rollers 99 and 99A are both overlapped by the corresponding upper and lower edges of the door 19. Thus, the door 19 is properly located vertically with respect to the rails 81 and 85.

The adjustment of the adjustment screws 122A is preferable also carried out in a manner to position the door 19 vertically so that the latch element 189 is properly located with respect to the latch opening in the astrogal 165 or lock block 194. With the door 19 so properly positioned, the astrogal opening 187 will receive the latch element 189 upon sliding of the door 19 to its closed position against the edge of the door 20 and raising of the latch element 189 will latch the two doors together by reason of overlapping of the leg 190 of the latch element 189 and the portion of the astrogal wall 167 of the opening 187. Such vertical adjustment of the door 19 is less critical when the second door 20 is omitted and the door 19 closes against a fixed stop 193 since the lock block 194 can be vertically adjusted by reason of slots 209 receiving the screws 210.

Should the rail 85 be other than perfectly level, so that the door 19 tends to rest thereon in a tilted rather than vertical position, the adjustment screws 122A of the lower roller assemblies may be further adjusted differentially to raise one of the lower comers of the door more than the other so that the door assumes an accurately vertical position to enable the side edges thereof to engage continuously, for example, the Weatherstripping 48 on the fixed window 16 (FIG. 6) and the astrogal 165 on the opposed door 20 (FIGS. 17-20) or, if no such opposed door is provided, the stile 193 (FIG. 21), when in its closed position to provide for complete weather or insect sealing and correct operation of the latching mechanism 34.

The door 19 is readily adapted to use with tracks 22 and 23 of different spacings without varying the position of the adjustment screw 125A and nut 114A (FIG. 13), by substitution of nuts 114A of a different height. More particularly then, a nut of different height communicated in broken lines in FIG. 13 at 1 14AA may be provided as a substitute for the nut 1 14A shown in solid lines to allow the pivot bar 91A to assume a higher of further inward limiting position as indicated in broken lines at 9lAA, for a given lateral adjustment of the nut. Alternatively, or in addition, nuts of different height can also be provided in the upper roller assemblies 79.

Following adjustment of the adjustment screws 122A of the lower roller assemblies 77 as above described, the adjustment screws 122 of the upper roller assembly 79 are adjusted, if required, to move the adjustment nuts 114 laterally therealong to predetermine the lower or inward limiting position of the pivot bars 91 and attached rollers 99. Normally, this adjustment is made to move the inward limiting position of the pivot bars 91 upwardly so that the rollers .99 can thereafter move downwardly only to a relatively minor extent away from the upper rail 81, normally to an extent little more than sufficient to allow sliding of the door to a fully open position and despite any nonparallelism of the rails 81 and 85. In this manner, it becomes impossible for the door to be. lifted, as by an intruder located on the outside of the door and seeking to gain unauthorized admittance to the building, to the extent required to disengage the lower edge of the door 19 from the rail and swing same exteriorily for removal of the door.

The above mentioned adjustment of the inner limiting position of the upper roller assembly 79 also precludes unauthorized opening of the door from the outside in another manner. More particularly, the latch element 189 is normally held in its upwardmost or locking position with respect to the astrogal of lock block 194 by a moderate amount of internal friction in the latch assembly 34 and by friction between the latch element 189 and the opposed face of the astrogal or lock block. An upward movement of the door 19 thus would not result in an upward movement of the latch element 189 therewith, upward movement of the latch element 189 being prevented by bearing thereof on the upper edge of the opening 187 (FIG. 17) or 208 (FIGS. 22 and 23). Thus, were the door was raised a distance greater than the height of the leg on the latch 189 and thereafter allowed to fall to its normal operating position wherein the pivot bars 91A engage the opposed adjustment blocks 114A of the lower roller assemblies 77, the latch element 189 will have been lowered with respect to the door to an extent sufficient that the latch element 189 as a wholecan be removed from the opening 187 or 208 simply by sliding the door 19 away from the astrogal 165 or stile 193 in a normal opening movement. However, by the above mentioned adjustment of the adjustment screws 122 of the upper roller assemblies, whereby the adjustment nuts 1 14 are moved laterally outwardly to raise the innermost or downward limiting position of the pivot bars 91 and rollers 99, the distance that the door 19 can be raised beforethe pivot bars 91 strike the nuts 114 can be limited g to a distance substantially less than the height of the leg 190 on the latch element 189. Thus, the door 19 cannot be raised sufficiently from the exterior thereof to move the latch element 189 to its lower or nonlocking position.

Still further, the unauthorized person seeking to gain admittance to the building has no access to the adjustment screws 122 and 122Asince the adjustment screws are either located in the iliterior of the building and shielded from tampering from the outside by the fixed window 16 or, on the other hand, are shielded from tampering from the exterior of the building by the astrogal 165 or stile 193. Thus, appropriate adjustment of the adjustment screws 122, resulting in a rigid or fixed inward limiting position for the pivot bars 91 positively precludes unauthorized entrance to the building by vertical manipulation of the latched door 19.

Thus, with the door so properly vertically positioned and aligned, sliding of the door rightwardly or leftwardly will effect closing or opening of the building portal to allow entrance'or exit therefrom.

To latch the door in its closed position, the door 19 is moved rightwardly to contact with the astrogal 165 and/or stile 193 whereby the latch element 189 is received in the corresponding opening 187 (FIGS. 17 through 20) or 208 (FIGS. 21 and 22). Upward movement of the latch element 189 results in overlapping of the leg 190 thereof with the portion of the wall 167 of the stile or wall 204 of the lock block 194 above the respective openings 187 and 208 to effect a latching of the door. Unlatching is carried out by lowering of the latch element. Normally, manually engagable means 34A (FIG. 2) for raising and lowering the latch element 189 are provided only on the interior side of the door precluding unlatching and opening of the door from the exterior.

Where two doors 19 and are provided, latching same together as above described prevents sliding movement of either door, by reason of interfingered engagement of the doors l9 and 20 with the corresponding windows 16 and 17, such interfingered engagement being shown for example at 41 and 42 (FIG. 6).

In addition to its latching function above discussed, the astrogal 165 by reason of its fixed attachement to the door 20 provides for weather or insect sealing and guiding of the door 19 upon closure thereof. More particularly, it will be seen from FIGS. 18 and l9'that upon rightward or closing movement'of the door 19, the rightward edge thereof will be brought into nesting relationship with the leftward face of the astrogal 165, the rightward edge of the door 19 being guided into proper closing coplanar relationship with the door 20 by reception of its exterior edge portion between the divergent wall 168 and crossarm 178 of the astrogal 165. Further, when the door 19 is closed as seen in FIG. 19, the configuration of the several abutting faces of the astrogal 165 and rightward edge of the door 19 provide a labyrinthian interface which provides an excellent weather or insect seal. Moreover, the labyrinthian and close abutting character of the fit between astrogal and rightward door edge precludes entry thereinto of strip material for unauthorized manipulation and unlatching of the latch member 189, again precluding unauthorized entry.

The closing, latching, door guiding, weather or insect sealing and strip insertion prevention features of the embodiment of FIGS. 21-23 are generally similar to those described above with respect to the astrogal equipped door 20 discussed above with respect to FIGS. 17-19. In addition, the latch block 194 may be adjusted upwardly and downwardly, by loosening of the screws 210 followed by a retightening thereof, to compensate for vertical mis'adjustment of the door 19 whereby proper latching and unlatching can be carried out despite such vertical misadjustment of the door 19.

FIG.'24 discloses a further modified formof the pivot bar as indicated at 91E which is similar to the bar 91C (FIG. 16) but differs therefrom in several particulars indicated below. The pivot bar 91E shown is intended for use on the upper edge of the door panel construction. The pivot bar 91E is wider than the pivot bar 91C, corresponding in width to the pivot bar 91 of FIG. 9, and is thus capable of substantially filling the space between the side walls of the top frame member 31. The pivot bar 91E is provided with a notch 101E for reception of the wheel 99E, as in the case of the pivot bar 91 of FIG. 9.

The pivot bar 91E provides for a strengthened and more secure mounting for the end of the spring 12913 in including a substantially U-shaped boss 212 on the underside thereof and beneath and somewhat longitudinally inwardly of the boss 155E utilized for mounting of the wheel 99E. The U-shaped boss 212 is at one end 213 thereof integral with the underside of the pivot bar a substantially L-shaped slot into which the corre-' sponding, substantially L-shaped end 217 of the spring 129E is receivable. The end 217 of the spring 129E is fixed within the U-shaped boss 212 and between the flange 215 thereof and the underface of the bar 91E by distorting the U-shaped flange 212 to move the end 214 thereof rightwardly and upwardly toward the end 212 thereof. An extension 218 of the pivot bar 91E extends rightwardly from the wheel mounting boss E along the upper surface of the spring 129E to provide an elongated backing surface for the leftward end of the spring which prevents any tendency of the leftward end of the spring to rock within the U-shaped boss 212 and thus enhances the rigid mounting of the spring when upwardly directed forces are applied to the rightward end 132E of the spring during use.

The thickness of the extension 218 is preverably less than that of the central portion of the bar 91B and further is preferably substantially that of the leftward extension 149E thereof.

As is the case of the pivot bar 91C of FIG. 16, the pivot bar 91E is adapted to manufacture by extrusion along the axes of the bosses 155E and 152E wherein individual pivot bars 91E may be transversely severed from such an elongated extrusion.

Pivot bars for the lower portion of the door (usable in the place of the pivot bar 91A inFIG. 13) may be constructed in a manner similar to the pivot bars of FIGS. 16 and 24 by omission of the corresponding spring 129C or 129E. In addition, for example in the case of FIG. 24, the extension 218 and U-shaped boss 212 with its flange 215 may also be omitted when the pivot bar is intended for use in the bottom frame 32 of the door.

FIG. 25 discloses a further modified limit block or nut construction 114F which like the nut construction 1148 of FIG. 5 is adapted for manufacture from an elongate extrusion by a transverse severing operation. The nut 114F has the above discussed advantages of the nut 1148 of FIG. 15 and in addition requires even less material to manufacture while retaining the requisite amount of strength. More particularly, the side faces 147F are substantially more extensively hollowed out than in the case of the nut 114B. Thus,the nut 114F comprises a generally T-shaped and upstanding top portion 219 from which integrally depends'a substantially A-shaped bottom portion 220. The upper end of the A-shaped portion includes a threaded opening 119F which opens, through a slot 146F, downwardly into the zone between the downwardly diverging legs of the A-shaped bottom portion 220.

Although a particular preferred embodiment of the invention has been disclosed in detail for illustrative purposes, it will be recognized that variations or modifications of the disclosed apparatus, including the rearrangement of parts, lie within the scope of the present invention.

The embodiments of the invention in which an exclusive property or privilege is claimed are defined as follows: I

1. A sliding door construction guided for sliding movement by a rail, comprising:

a door adjacent said rail, said door comprising a frame-work including spaced side members and spaced transverse channel members of outwardly opening channel cross section connecting said side members adjacent the ends thereof;

a guidable element engageable with said rail;

mentioned path at which said limitation of movement of said support means occurs; adjustment means accessible from the outside of the door and manipulatable for adjusting the position of said abutment element on said second path; at least one pair each of guidable elements, movable support means, abutment elements and adjustment means being received in each channel member, said side members having opposed notched portions snugly receiving the adjacent ends of said transverse members having spaced opposed sidewalls connected by a bight wall, said sidewalls having outward extensions of increased spacing lying beyond and abutting the ends of said side members, a hollow rib on one said wall extending longitudinally of said transverse member, elongate fastening means receivable in said rib and engaging the adjacent side member for fastening the transverse members to the side members, said abutment element comprising a block supported for sliding movement on the walls of said channel member and having a recessed portion receiving said rib. 2. The device defined in claim 1 in which said adjustment means comprises a screw substantially parallel to said rib and threadedly engaging said block, said screw being axially fixed with respect to the adjacent side member whereby rotation of said screw will cause the block to move longitudinally of said channel adjacent said rib, said movable support means comprising a bar pivotally supported between the sidewalls of said channel adjacent said screw, said block lying in the pivotal,

path of said bar for limiting inward movement of said guidable element with respect to said door.

3. A sliding door construction guided for sliding movement by a rail, comprising:

a door adjacent said rail; a guidable element engageable with said rail; movable support means carrying said guidable element and securing same to said door for movement through a selected path; an abutment element capable of interfering contact with said movable support means to limit movement of said support means on said first mentioned path, said abutment element being movable along a second path to change the position on said first mentioned path at which said limitation of movement of said support means occurs; adjustment means accessible from the outside of the door and manipulatable for adjusting the position of said abutment element on said second path; a second door substantially coplanar to said first mentioned door; an elongate astragal secured to the edge of one of said doors, said astragal comprising a first portion of generally C-shaped cross section and a second portion of generally T-shaped cross section having a crossarm and a leg, said leg being integrally connected to said portion of C-shaped cross section adjacent to but spaced from one edge thereof, said doors having opposed concave end faces, said crossarm being disposed exteriorly of said doors, said leg extending between said doors and one portion of said C-shaped portion being snugly receivable in the concave end face of one door and the remaining portion of said C-shaped portion being snugly receivable in the concave end face of the other door for effecting a labyrinthian interface therebetween.

4. The device defined in claim 3 in which said second door carries further guidable elements, movable support means, abutment elements and adjustments means, said astragal including openings in said C- shaped portion for providing access to said adjustment means of said one door, a latch element in the concave end face of the other door extending towards said one door, said astragal having an opposed opening for coacting with said latch element for latching said doors together in relatively immovable relationship.

5. The device defined in claim 4 in which said astragal is notched at an end thereof for reception of said rail in clearance relation therein.

6. A sliding door construction guided for sliding movement by a rail, comprising:

a door adjacent said rail;

a guidable element engageable with said rail;

movable support means carrying said guidable element and securing same to said door for movement through a selected path;

an abutment element capable of interfering contact with said movable support means to limit movement of said support means on said first mentioned path, said abutment element being movable along a second path to change the position on said first mentioned path at which said limitation of movement of said support means occurs;

adjustment means accessible from the outside of the door and manipulatablefor adjusting the position of said abutment element on said second path; latch means on one edge of said door; a fixed stile in the path of said door, said stile having a stepped face opposed to said door; and

a latch block fixed to one of the steps of said stile and having an opening therein for reception of said latch means on said door for latching said door to said stile, said latch block having a recess facing transversely of the plane of said door and closed by the opposed surface of said one step, said opening communicating with said recess.

7. The device defined in claim 6 in which the latch block recess is defined by an interior face from which transversely extend an opposed pair of end walls and an opposed pair of sidewalls connecting said end walls, one of said sidewalls having said opening therein for reception into the interior of said latch block of said latch means of said door, elongate slots in the interior face of said latch blocks for reception thereinto of screws engagable with said stile for holding said latch block thereto, said latch block being adjustable along the length of said stile to an extent dependent on the length dimension of said slots for properly positioning the opening in said latch block with respect to the latch on said door.

8. In a door construction slidable between a vertically spaced pair of rails, a combination comprising:

a door framework comprising a spaced opposed pair of upstanding side members and a spaced opposed ment in a plane substantially parallel to and between said sidewalls; a roller adjacent the opposite end of said pivot bar and guidedly engageable with said rail;

a nut disposed between said sidewalls in said channel and supported upon the bight wall of said channel connecting said sidewalls for sliding movement longitudinally of the channel, said nut being disposed inwardly of said pivot bar with respect to said door, said nut having an abutment surface capable of contact by said pivot bar for precluding further inward movement of said pivot bar with respect to said door and towards said bight wall of said channel, the length axis of said pivot bar being inclined with respect to said bight wall when saidtpivot bar is in contact with said abutment surface in a manner that the portion of the length axis of said pivot bar adjacent said abutment nut is further from said bight wall than the portion of said axis adjacent said pivot mounting of said bar, whereby movement of said abutment nut along the bight wall towards the pivot axis pivotally moves said pivot bar in a direction for moving said roller away from said bight wall; an elongate adjustment screw extending along said pivot bar and threadedly engaging said nut, said ad justment screw being substantially parallel said bight wall, whereupon rotation of said adjustment screw causes said nut to move along said bight wall to adjust the inwardmost limiting position of said pivot bar; resilient means disposed between said nut and a fixed wall defining the end of said channel and means defining a head on said screw disposed on the opposite sideof said fixed wall from said resilient means, said resilient meansand head cooperating to maintain said adjustment screw in substantially fixed relationship with respect to said door while not precludingv rotation thereof. 9. The device defined in claim 8 in which said resilient means comprises a coil spring coaxially receiving said adjustment screw therewithin and including means preventing unintentional threaded movement of said nut off said screw.

10. The device defined in claim 8 including an elongate sinuously curved leaf spring releasably secured at one end thereof to the end of said pivot bar carrying said roller and normally bearing at its other end upon means fixed with respect to said bottom wall for urging said pivot bar outwardly of said door construction, there being at least two pivot bars equipped with such sinuously curved springs, one at each end of said upper frame member, there being two further such pivot bars disposed adjacent the ends of the bottom frame member and having no such spring.

11. The device defined in claim 8 in which said nut comprises a severed length of an extrusion having generally rectilinear form, having recessed portions in opposed sidewalls thereof normally disposed opposite to the sidewalls of the channel of the corresponding top or bottom frame member, a threaded opening therethrough for reception of said adjustment screw therein and a slot communicating between said threaded opening and exterior face of said block.

12. The device defined in claim 8 in which said pivot bar comprises a plate-like element having an extension which is angled at a shallow angle with respect to the central plane of said plate-like portion, said extension being angled to allow clearance of said pivot bar and said adjustment screw, spaced slotted bosses extending transverselyof said pivot bar on one face thereof for reception of the pivot pin and means for supporting said roller and further slot adjacent the roller carrying end of said pivot bar, said spring having an L-shaped end thereon engageable within said slot, theend portion of said bar defining said slot being deformable into close pressed relationship with said end of said spring for holding said spring in fixed relationship to said bar.

13. The device defined in claim 8in which the pivot bar comprises a plate-like element having a first extension at one end thereof angled at a shallow angle with respect to the central plane of said plane-like portion, said first extension being angled to allow clearance of said pivot bar and said adjustment screw, spaced slotted bosses extending transversely of said pivot bar on one face thereof for reception of said pivot pin and means for supporting said roller, a substantially U- shaped boss on the side of said pivot bar opposite said slotted bosses and located substantially opposite the one of said bosses receiving said means for supporting said roller, one leg of said U-shaped boss being spaced from the opposed side of said pivot bar for defining therewith an L-shaped slot, said spring having L-shaped end engageable within said slot, said U-shaped boss being deformable intoclose spaced relationship with the end of said spring for holding same in fixed relation to said bar, said bar having a second extension extending beyond said last mentioned slotted boss for backing the portion of said spring adjacent the L-shaped end thereof.

14. A sliding door construction including a door guided for sliding movement by a rail, comprising:

a guidable element engageable with said rail;

an elongate bar and pivot means adjacent one end of said bar for pivotally mounting said bar on said door, said guidable element being mounted adjacent the other end of said bar, said other end of said bar extending at a shallow angle to said rail so that movement of said guidable element is predominantly toward and away from said rail;

means defining a limit block movable on said door along a path adjacent a portion of said bar intermediate said pivot means and guidable element and engageable with said intermediate portion of said bar for limiting movement of said guidable element inwardly of said door, said limit block comprising a nut supported for sliding motion on said door along a path substantially parallel to said rail and intersected by said other end of said bar, said nut being contractable by said bar for limiting inward pivotal movement of said bar, movement of said nut in one direction along said path of travel progressively moving the inward limiting position of said bar outwardly of the door;

adjustment means accessible from the outside of the door for adjusting the position of said limit block on said path and lying adjacent said one end of said bar for limiting movement of said guidable element outwardly of said door, said adjustment means comprising an adjustment screw threadedly engaging said nut and rotatable for moving said nut along its path and further including means at least resiliently urging said screw to remain in a longitudinally fixed position with respect to said door.

15. The device defined in claim 14, including spring means mounted on said other end of said bar and spaced from said pivot means at least substantially as far as in said guidable means for urging said bar outwardly of said door.

16. A sliding door construction including a door guided for sliding movement by a rail, comprising:

a guidable element engageable with said rail;

an elongate bar and pivot means adjacent one end of said bar for pivotally mounting said bar on said door, said guidable element being mounted adjacent the other end of said bar;

means defining a limit block movable on said door along a path adjacent a portion of said bar intermediate said pivot means and guidable element and engageable with said intermediate portion of said bar for limiting movement of said guidable element inwardly of said door;

said bar comprising an extrusion segment including spaced parallel bosses on one side of said bar, said bosses extending and being slotted transversely of said bar and located at opposite ends of said intermediate portion, said guidable element and pivot means including pins receivable in said bosses, said one bar end extending from the adjacent boss and being angled toward said one bar side, said bar including a further boss adjacent the other bar end and facing oppositely of the adjacent first mentioned boss and defining a substantially L-shaped slot opening toward said other bar end, said bar being relieved adjacent said other bar end for receiving said guidable element;

a leaf spring adapted to bear against the door and having an L-shapedend received in said L-shaped slot and gripped by said further boss; and

adjustment means accessible from the outside of the door for adjusting the position of said limit block on said path and lying adjacent said one end of said bar for limiting movement of said guidable element outwardly of said door.

17. The device defined in claim 16 in which said adjustment means comprises a screw and said limit block comprises a nut threadedly engageable with said screw and movable with respedt to said door inboard of said bar upon rotation of said screw.

18. A sliding door construction including a door guided for sliding movement by a rail, comprising:

a guidable element engageable with said rail;

an elongate bar and pivot means adjacent one end of said bar for pivotally mounting said bar on said door, said guidable element being mounted adjacent the other end of said bar;

means defining a limit block movable on said door along a path adjacent a portion of said bar intermediate said pivot means and guidable element and engageable with said intermediate portion of said bar for limiting movement of said guidable element inwardly of said door;

adjustment means accessible from the outside of the door for adjusting the position of said limit block on said path and lying adjacent said one end of said bar for limiting movement of said guidable element outwardly of said door; and

first and second substantially coplanar doors and an.

elongate astragal secured to the edge of one of said doors, said astragal comprising a first portion of generally C-shaped cross section and a second portion of generally T-shaped cross section having a crossarm and a leg, said leg being integrally connected to said portion of C-shaped cross section adjacent to but spaced from one edge thereof, said doors having opposed concave end faces, said crossarm being disposed exteriorly of said doors, said leg extending between said doors and one portion of said C-shaped portion being snugly receivable in the concave end face of one door and the remaining portion of said C-shaped portion being snugly receivable in the concave end face of the other door for effecting a labyrinthian interface therebetween.

19. A sliding door construction including a door guided for sliding movement by a rail, comprising:

a guidable element engageable with said rail;

an elongate bar and pivot means adjacent one end of said bar for pivotally mounting said bar on said door, said guidable element being mounted adjacent the other end of said bar;

means defining a limit block movable on said door along a path adjacent a portion of said bar intermediate said pivot means and guidable element and engageable with said intermediate portion of said bar for limiting movement of said guidable element inwardly of said door;

adjustment means accessible from the outside of the door for adjusting the position of said limit block on said path and lying adjacent said one end of said bar for limiting movement of said guidable element outwardly of said door; and

latch means on one edge of said door, a fixed stile in the path of said door, said stile having a stepped face opposed to said door, a latch block fixed to one of the steps of said stile and having an opening therein for reception of said latch means on said door for latching said door to said stile, said latch block having a recess facing transversely of the plane of said door and closed by the opposed surface of said one step, said opening communicating with said recess. 

1. A sliding door construction guided for sliding movement by a rail, comprising: a door adjacent said rail, said door comprising a frame-work including spaced side members and spaced transverse channel members of outwardly opening channel cross section connecting said side members adjacent the ends thereof; a guidable element engageable with said rail; movable support means carrying said guidable element and securing same to said door for movement through a selected path; an abutment element capable of interfering contact with said movable support means to limit movement of said support means on said first mentioned path, said abutment element being movable along a second path tO change the position on said first mentioned path at which said limitation of movement of said support means occurs; adjustment means accessible from the outside of the door and manipulatable for adjusting the position of said abutment element on said second path; at least one pair each of guidable elements, movable support means, abutment elements and adjustment means being received in each channel member, said side members having opposed notched portions snugly receiving the adjacent ends of said transverse members having spaced opposed sidewalls connected by a bight wall, said sidewalls having outward extensions of increased spacing lying beyond and abutting the ends of said side members, a hollow rib on one said wall extending longitudinally of said transverse member, elongate fastening means receivable in said rib and engaging the adjacent side member for fastening the transverse members to the side members, said abutment element comprising a block supported for sliding movement on the walls of said channel member and having a recessed portion receiving said rib.
 2. The device defined in claim 1 in which said adjustment means comprises a screw substantially parallel to said rib and threadedly engaging said block, said screw being axially fixed with respect to the adjacent side member whereby rotation of said screw will cause the block to move longitudinally of said channel adjacent said rib, said movable support means comprising a bar pivotally supported between the sidewalls of said channel adjacent said screw, said block lying in the pivotal path of said bar for limiting inward movement of said guidable element with respect to said door.
 3. A sliding door construction guided for sliding movement by a rail, comprising: a door adjacent said rail; a guidable element engageable with said rail; movable support means carrying said guidable element and securing same to said door for movement through a selected path; an abutment element capable of interfering contact with said movable support means to limit movement of said support means on said first mentioned path, said abutment element being movable along a second path to change the position on said first mentioned path at which said limitation of movement of said support means occurs; adjustment means accessible from the outside of the door and manipulatable for adjusting the position of said abutment element on said second path; a second door substantially coplanar to said first mentioned door; an elongate astragal secured to the edge of one of said doors, said astragal comprising a first portion of generally C-shaped cross section and a second portion of generally T-shaped cross section having a crossarm and a leg, said leg being integrally connected to said portion of C-shaped cross section adjacent to but spaced from one edge thereof, said doors having opposed concave end faces, said crossarm being disposed exteriorly of said doors, said leg extending between said doors and one portion of said C-shaped portion being snugly receivable in the concave end face of one door and the remaining portion of said C-shaped portion being snugly receivable in the concave end face of the other door for effecting a labyrinthian interface therebetween.
 4. The device defined in claim 3 in which said second door carries further guidable elements, movable support means, abutment elements and adjustments means, said astragal including openings in said C-shaped portion for providing access to said adjustment means of said one door, a latch element in the concave end face of the other door extending towards said one door, said astragal having an opposed opening for coacting with said latch element for latching said doors together in relatively immovable relationship.
 5. The device defined in claim 4 in which said astragal is notched at an end thereof for reception of said rail in clearance relation therein.
 6. A sliding door construction guided for sliding movement by A rail, comprising: a door adjacent said rail; a guidable element engageable with said rail; movable support means carrying said guidable element and securing same to said door for movement through a selected path; an abutment element capable of interfering contact with said movable support means to limit movement of said support means on said first mentioned path, said abutment element being movable along a second path to change the position on said first mentioned path at which said limitation of movement of said support means occurs; adjustment means accessible from the outside of the door and manipulatable for adjusting the position of said abutment element on said second path; latch means on one edge of said door; a fixed stile in the path of said door, said stile having a stepped face opposed to said door; and a latch block fixed to one of the steps of said stile and having an opening therein for reception of said latch means on said door for latching said door to said stile, said latch block having a recess facing transversely of the plane of said door and closed by the opposed surface of said one step, said opening communicating with said recess.
 7. The device defined in claim 6 in which the latch block recess is defined by an interior face from which transversely extend an opposed pair of end walls and an opposed pair of sidewalls connecting said end walls, one of said sidewalls having said opening therein for reception into the interior of said latch block of said latch means of said door, elongate slots in the interior face of said latch blocks for reception thereinto of screws engagable with said stile for holding said latch block thereto, said latch block being adjustable along the length of said stile to an extent dependent on the length dimension of said slots for properly positioning the opening in said latch block with respect to the latch on said door.
 8. In a door construction slidable between a vertically spaced pair of rails, a combination comprising: a door framework comprising a spaced opposed pair of upstanding side members and a spaced opposed pair of substantially horizontal top and bottom members fixedly connecting said side members and being of substantially channel-like and upwardly and downwardly opening cross-section, respectively; a pivot bar located in one of said top and bottom members, said pivot bar being disposed between the sidewalls of said channel and pivotally supported by a pin extending between said walls, said pin being located adjacent the end of said pivot bar nearest the adjacent side member of said frame for pivotally mounting said pivot bar for pivotal movement in a plane substantially parallel to and between said sidewalls; a roller adjacent the opposite end of said pivot bar and guidedly engageable with said rail; a nut disposed between said sidewalls in said channel and supported upon the bight wall of said channel connecting said sidewalls for sliding movement longitudinally of the channel, said nut being disposed inwardly of said pivot bar with respect to said door, said nut having an abutment surface capable of contact by said pivot bar for precluding further inward movement of said pivot bar with respect to said door and towards said bight wall of said channel, the length axis of said pivot bar being inclined with respect to said bight wall when said pivot bar is in contact with said abutment surface in a manner that the portion of the length axis of said pivot bar adjacent said abutment nut is further from said bight wall than the portion of said axis adjacent said pivot mounting of said bar, whereby movement of said abutment nut along the bight wall towards the pivot axis pivotally moves said pivot bar in a direction for moving said roller away from said bight wall; an elongate adjustment screw extending along said pivot bar and threadedly engaging said nut, said adjustment screw being substantially parallel said bight wall, whereupon rotation of said adjuStment screw causes said nut to move along said bight wall to adjust the inwardmost limiting position of said pivot bar; resilient means disposed between said nut and a fixed wall defining the end of said channel and means defining a head on said screw disposed on the opposite side of said fixed wall from said resilient means, said resilient means and head cooperating to maintain said adjustment screw in substantially fixed relationship with respect to said door while not precluding rotation thereof.
 9. The device defined in claim 8 in which said resilient means comprises a coil spring coaxially receiving said adjustment screw therewithin and including means preventing unintentional threaded movement of said nut off said screw.
 10. The device defined in claim 8 including an elongate sinuously curved leaf spring releasably secured at one end thereof to the end of said pivot bar carrying said roller and normally bearing at its other end upon means fixed with respect to said bottom wall for urging said pivot bar outwardly of said door construction, there being at least two pivot bars equipped with such sinuously curved springs, one at each end of said upper frame member, there being two further such pivot bars disposed adjacent the ends of the bottom frame member and having no such spring.
 11. The device defined in claim 8 in which said nut comprises a severed length of an extrusion having generally rectilinear form, having recessed portions in opposed sidewalls thereof normally disposed opposite to the sidewalls of the channel of the corresponding top or bottom frame member, a threaded opening therethrough for reception of said adjustment screw therein and a slot communicating between said threaded opening and exterior face of said block.
 12. The device defined in claim 8 in which said pivot bar comprises a plate-like element having an extension which is angled at a shallow angle with respect to the central plane of said plate-like portion, said extension being angled to allow clearance of said pivot bar and said adjustment screw, spaced slotted bosses extending transversely of said pivot bar on one face thereof for reception of the pivot pin and means for supporting said roller and further slot adjacent the roller carrying end of said pivot bar, said spring having an L-shaped end thereon engageable within said slot, the end portion of said bar defining said slot being deformable into close pressed relationship with said end of said spring for holding said spring in fixed relationship to said bar.
 13. The device defined in claim 8 in which the pivot bar comprises a plate-like element having a first extension at one end thereof angled at a shallow angle with respect to the central plane of said plane-like portion, said first extension being angled to allow clearance of said pivot bar and said adjustment screw, spaced slotted bosses extending transversely of said pivot bar on one face thereof for reception of said pivot pin and means for supporting said roller, a substantially U-shaped boss on the side of said pivot bar opposite said slotted bosses and located substantially opposite the one of said bosses receiving said means for supporting said roller, one leg of said U-shaped boss being spaced from the opposed side of said pivot bar for defining therewith an L-shaped slot, said spring having L-shaped end engageable within said slot, said U-shaped boss being deformable into close spaced relationship with the end of said spring for holding same in fixed relation to said bar, said bar having a second extension extending beyond said last mentioned slotted boss for backing the portion of said spring adjacent the L-shaped end thereof.
 14. A sliding door construction including a door guided for sliding movement by a rail, comprising: a guidable element engageable with said rail; an elongate bar and pivot means adjacent one end of said bar for pivotally mounting said bar on said door, said guidable element being mounted adjacent thE other end of said bar, said other end of said bar extending at a shallow angle to said rail so that movement of said guidable element is predominantly toward and away from said rail; means defining a limit block movable on said door along a path adjacent a portion of said bar intermediate said pivot means and guidable element and engageable with said intermediate portion of said bar for limiting movement of said guidable element inwardly of said door, said limit block comprising a nut supported for sliding motion on said door along a path substantially parallel to said rail and intersected by said other end of said bar, said nut being contractable by said bar for limiting inward pivotal movement of said bar, movement of said nut in one direction along said path of travel progressively moving the inward limiting position of said bar outwardly of the door; adjustment means accessible from the outside of the door for adjusting the position of said limit block on said path and lying adjacent said one end of said bar for limiting movement of said guidable element outwardly of said door, said adjustment means comprising an adjustment screw threadedly engaging said nut and rotatable for moving said nut along its path and further including means at least resiliently urging said screw to remain in a longitudinally fixed position with respect to said door.
 15. The device defined in claim 14, including spring means mounted on said other end of said bar and spaced from said pivot means at least substantially as far as in said guidable means for urging said bar outwardly of said door.
 16. A sliding door construction including a door guided for sliding movement by a rail, comprising: a guidable element engageable with said rail; an elongate bar and pivot means adjacent one end of said bar for pivotally mounting said bar on said door, said guidable element being mounted adjacent the other end of said bar; means defining a limit block movable on said door along a path adjacent a portion of said bar intermediate said pivot means and guidable element and engageable with said intermediate portion of said bar for limiting movement of said guidable element inwardly of said door; said bar comprising an extrusion segment including spaced parallel bosses on one side of said bar, said bosses extending and being slotted transversely of said bar and located at opposite ends of said intermediate portion, said guidable element and pivot means including pins receivable in said bosses, said one bar end extending from the adjacent boss and being angled toward said one bar side, said bar including a further boss adjacent the other bar end and facing oppositely of the adjacent first mentioned boss and defining a substantially L-shaped slot opening toward said other bar end, said bar being relieved adjacent said other bar end for receiving said guidable element; a leaf spring adapted to bear against the door and having an L-shaped end received in said L-shaped slot and gripped by said further boss; and adjustment means accessible from the outside of the door for adjusting the position of said limit block on said path and lying adjacent said one end of said bar for limiting movement of said guidable element outwardly of said door.
 17. The device defined in claim 16 in which said adjustment means comprises a screw and said limit block comprises a nut threadedly engageable with said screw and movable with respedt to said door inboard of said bar upon rotation of said screw.
 18. A sliding door construction including a door guided for sliding movement by a rail, comprising: a guidable element engageable with said rail; an elongate bar and pivot means adjacent one end of said bar for pivotally mounting said bar on said door, said guidable element being mounted adjacent the other end of said bar; means defining a limit block movable on said door along a path adjacent a portion of said bar intermediate said pivot means and guidable element and engageAble with said intermediate portion of said bar for limiting movement of said guidable element inwardly of said door; adjustment means accessible from the outside of the door for adjusting the position of said limit block on said path and lying adjacent said one end of said bar for limiting movement of said guidable element outwardly of said door; and first and second substantially coplanar doors and an elongate astragal secured to the edge of one of said doors, said astragal comprising a first portion of generally C-shaped cross section and a second portion of generally T-shaped cross section having a crossarm and a leg, said leg being integrally connected to said portion of C-shaped cross section adjacent to but spaced from one edge thereof, said doors having opposed concave end faces, said crossarm being disposed exteriorly of said doors, said leg extending between said doors and one portion of said C-shaped portion being snugly receivable in the concave end face of one door and the remaining portion of said C-shaped portion being snugly receivable in the concave end face of the other door for effecting a labyrinthian interface therebetween.
 19. A sliding door construction including a door guided for sliding movement by a rail, comprising: a guidable element engageable with said rail; an elongate bar and pivot means adjacent one end of said bar for pivotally mounting said bar on said door, said guidable element being mounted adjacent the other end of said bar; means defining a limit block movable on said door along a path adjacent a portion of said bar intermediate said pivot means and guidable element and engageable with said intermediate portion of said bar for limiting movement of said guidable element inwardly of said door; adjustment means accessible from the outside of the door for adjusting the position of said limit block on said path and lying adjacent said one end of said bar for limiting movement of said guidable element outwardly of said door; and latch means on one edge of said door, a fixed stile in the path of said door, said stile having a stepped face opposed to said door, a latch block fixed to one of the steps of said stile and having an opening therein for reception of said latch means on said door for latching said door to said stile, said latch block having a recess facing transversely of the plane of said door and closed by the opposed surface of said one step, said opening communicating with said recess. 